java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widg

有时候需要在在代码中设置LayoutParams,自己为一个FrameLayout设置LayoutParams的时候,遇上如题问题:

1
java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams<br>

FrameLayout的父控件是一个LinearLayout控件,问题出在,LinearLayout为子控件分配空间的时候,获取FrameLayout的LayoutParams的必须为LinearLayout.LayoutParams,而非FrameLayout.LayoutParams。

简单的举个栗子说明一下:最外层有ReLativeLayout A,里面有两个LinearLayout B、C,而B中又有一个一个FrameLayout D。如果要在代码里设置B的LayoutParams,B的LayoutParams要为RelativeLayout.LayoutParams。

1
2
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
    B.setLayoutParams(params);

 而D要设置的话,需要:

1
2
3
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, 0);
    params.weight = 8;
    D.setLayoutParams(params);

 

 

 

 

 

 

 

 

 

java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widg,布布扣,bubuko.com

java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widg

上一篇:Android WebView属性及用法


下一篇:【6】nagios从零学习使用 - centreon发送邮件报警